thermly

Free NZ postcode tool · H1/AS1 Sixth Edition

Find your H1 climate zone by postcode.

Get a fast postcode estimate, confirm the council that Appendix C uses, then carry the right zone into the H1/AS1 Calculation Method.

Climate zones
6
Councils
69
Source
Appendix C

Checked against H1/AS1 Sixth Edition on

In force from 27 November 2025. Postcode results are estimates; the H1/AS1 territorial-authority table is authoritative.

H1 climate zone postcode lookup

Start with the postcode. Finish with the council.

NZ Post delivery areas and H1 climate-zone boundaries are different geographies. The postcode narrows the answer; your territorial authority confirms it.

Source of truth: H1/AS1 Sixth Edition, Table C.1.1.2.

New Zealand H1 zones 1–6

Popular H1 climate zone answers.

Each card lists the territorial authorities Appendix C assigns to that zone, because councils are the basis of the boundary. Region names are not: several regions span two or three zones. Rangitikei and Waitaki districts are split geographically and appear in two zones each.

Climate zone

Zone 1

The warmest zone. Neighbouring Hauraki District and Waikato District are Zone 2, and inland Rotorua District is Zone 4.

Territorial authorities (10)

Far North District · Whangarei District · Kaipara District · Auckland · Thames-Coromandel District · Western Bay of Plenty District · Tauranga City · Whakatane District · Kawerau District · Ōpōtiki District

Example localities

Whangārei (Whangarei District) · Auckland · Tauranga (Tauranga City) · Whakatāne (Whakatane District)

Climate zone

Zone 2

Region names do not decide the zone here: Thames-Coromandel District is Zone 1, and Taupo District and Rotorua District are Zone 4.

Territorial authorities (17)

Hauraki District · Waikato District · Matamata-Piako District · Hamilton City · Waipa District · Ōtorohanga District · South Waikato District · Waitomo District · Gisborne District · Wairoa District · Hastings District · Napier City · Central Hawke's Bay District · New Plymouth District · Stratford District · South Taranaki District · Whanganui District

Example localities

Hamilton (Hamilton City) · Gisborne (Gisborne District) · Napier (Napier City) · New Plymouth (New Plymouth District)

Climate zone

Zone 3

Wellington City, Porirua City and Lower Hutt City are Zone 3, but Upper Hutt City is Zone 4. Only the part of Rangitikei District south of 39°50'S is Zone 3.

Territorial authorities (13)

Rangitikei District, south of 39°50'S (-39.83) · Manawatu District · Palmerston North City · Horowhenua District · Kapiti Coast District · Porirua City · Lower Hutt City · Wellington City · Tasman District · Nelson City · Marlborough District · Kaikoura District · Chatham Islands

Example localities

Palmerston North (Palmerston North City) · Wellington (Wellington City) · Nelson (Nelson City) · Blenheim (Marlborough District)

Climate zone

Zone 4

Takes in Upper Hutt City and the whole Wairarapa, the three West Coast districts, and Rangitikei District north of 39°50'S.

Territorial authorities (12)

Taupo District · Rotorua District · Ruapehu District · Rangitikei District, north of 39°50'S (-39.83) · Tararua District · Upper Hutt City · Masterton District · Carterton District · South Wairarapa District · Buller District · Grey District · Westland District

Example localities

Rotorua (Rotorua District) · Taupō (Taupo District) · Masterton (Masterton District) · Greymouth (Grey District)

Climate zone

Zone 5

Canterbury from Hurunui District to Waimate District, plus Dunedin City and Clutha District. Kaikoura District to the north is Zone 3, and Mackenzie District inland is Zone 6.

Territorial authorities (10)

Hurunui District · Waimakariri District · Christchurch City · Selwyn District · Ashburton District · Timaru District · Waimate District · Waitaki District, true right of the Otekaieke river · Dunedin City · Clutha District

Example localities

Christchurch (Christchurch City) · Timaru (Timaru District) · Dunedin (Dunedin City) · Balclutha (Clutha District)

Climate zone

Zone 6

The alpine and inland South Island councils plus all three Southland councils. Waitaki District is Zone 6 only on the true left of the Otekaieke river.

Territorial authorities (7)

Mackenzie District · Waitaki District, true left of the Otekaieke river · Central Otago District · Queenstown-Lakes District · Southland District · Gore District · Invercargill City

Example localities

Twizel (Mackenzie District) · Queenstown (Queenstown-Lakes District) · Alexandra (Central Otago District) · Invercargill (Invercargill City)

H1/AS1 Sixth Edition · Table C.1.1.2

Every New Zealand council and its H1 climate zone.

69 rows, in the order Appendix C prints them. This table is the authoritative answer; the postcode lookup above is only an estimate of which row applies to you.

North Island / Te Ika-a-Māui

North Island / Te Ika-a-Māui territorial authorities and their H1/AS1 Sixth Edition climate zones, from Table C.1.1.2.
Territorial authorityClimate zone
Far North DistrictZone 1
Whangarei DistrictZone 1
Kaipara DistrictZone 1
AucklandZone 1
Thames-Coromandel DistrictZone 1
Hauraki DistrictZone 2
Waikato DistrictZone 2
Matamata-Piako DistrictZone 2
Hamilton CityZone 2
Waipa DistrictZone 2
Ōtorohanga DistrictZone 2
South Waikato DistrictZone 2
Waitomo DistrictZone 2
Taupo DistrictZone 4
Western Bay of Plenty DistrictZone 1
Tauranga CityZone 1
Rotorua DistrictZone 4
Whakatane DistrictZone 1
Kawerau DistrictZone 1
Ōpōtiki DistrictZone 1
Gisborne DistrictZone 2
Wairoa DistrictZone 2
Hastings DistrictZone 2
Napier CityZone 2
Central Hawke's Bay DistrictZone 2
New Plymouth DistrictZone 2
Stratford DistrictZone 2
South Taranaki DistrictZone 2
Ruapehu DistrictZone 4
Whanganui DistrictZone 2
Rangitikei Districtnorth of 39°50'S (-39.83)Zone 4
Rangitikei Districtsouth of 39°50'S (-39.83)Zone 3
Manawatu DistrictZone 3
Palmerston North CityZone 3
Tararua DistrictZone 4
Horowhenua DistrictZone 3
Kapiti Coast DistrictZone 3
Porirua CityZone 3
Upper Hutt CityZone 4
Lower Hutt CityZone 3
Wellington CityZone 3
Masterton DistrictZone 4
Carterton DistrictZone 4
South Wairarapa DistrictZone 4

South Island / Te Waipounamu

South Island / Te Waipounamu territorial authorities and their H1/AS1 Sixth Edition climate zones, from Table C.1.1.2.
Territorial authorityClimate zone
Tasman DistrictZone 3
Nelson CityZone 3
Marlborough DistrictZone 3
Kaikoura DistrictZone 3
Buller DistrictZone 4
Grey DistrictZone 4
Westland DistrictZone 4
Hurunui DistrictZone 5
Waimakariri DistrictZone 5
Christchurch CityZone 5
Selwyn DistrictZone 5
Ashburton DistrictZone 5
Timaru DistrictZone 5
Mackenzie DistrictZone 6
Waimate DistrictZone 5
Chatham IslandsZone 3
Waitaki Districttrue left of the Otekaieke riverZone 6
Waitaki Districttrue right of the Otekaieke riverZone 5
Central Otago DistrictZone 6
Queenstown-Lakes DistrictZone 6
Dunedin CityZone 5
Clutha DistrictZone 5
Southland DistrictZone 6
Gore DistrictZone 6
Invercargill CityZone 6

Rangitikei District is split at 39°50'S and Waitaki District at the Otekaieke river, so each appears twice with a different zone. For an address in either district, the geographic line decides the zone, not the district name.

Read the result correctly

A climate zone feeds the heat-loss comparison.

Under the Sixth Edition Calculation Method, the selected zone changes parts of the reference building. It does not turn every number in the reference table into a standalone minimum for your proposed construction.

Reference-building coefficients

H1/AS1 Table 2.1.2.7 supplies values for roof plus skylight, opaque wall, slab-on-ground, other floors and the reference building's 30% wall glazing. Thermly applies them in the whole-building reference heat-loss equation.

Separate non-tradeable minimums

Section 2.1.2.11 sets construction R-value floors of R2.6 for roofs, R1.0 for walls and R1.3 for floors other than slabs. Slab-on-ground floors have no minimum in that clause. The Calculation Method also caps wall glazing at 40% of gross wall area.

Why council confirmation matters

Postcodes describe delivery areas. H1 zones follow council boundaries, with explicit geographic splits for two districts. Use the finder for speed, then record the territorial-authority basis in the consent evidence.

Climate zone FAQ

Common H1 climate zone questions.

What H1 climate zone is my postcode in?
Enter the four-digit postcode above for a quick estimate, then confirm the territorial authority. H1/AS1 defines the six climate zones by territorial-authority boundaries, not postal boundaries.
How many H1 climate zones are there in New Zealand?
H1/AS1 Sixth Edition has six climate zones. Zone 1 covers the warmest northern areas, while Zones 5 and 6 cover colder southern and alpine areas, but the official council table is the source of truth.
Is a postcode enough to select an H1 climate zone?
A postcode is useful for an estimate, but it is not authoritative. Postcode delivery areas can cross council or H1 boundaries. Appendix C says its territorial-authority table takes precedence over the climate-zone map.
Are the reference R-values minimum insulation requirements?
No. The Table 2.1.2.7 values are reference-building coefficients used in the Calculation Method heat-loss equation. H1/AS1 also sets separate non-tradeable construction R-value minimums for roofs, walls and floors other than slabs.
Which H1 zones are Auckland, Wellington and Christchurch in?
Auckland is Zone 1, Wellington City is Zone 3, and Christchurch City is Zone 5. Nearby councils can differ: Upper Hutt City, for example, is Zone 4.

From zone to calculation

A zone on its own does not show compliance.

Whether you are designing the house, pricing it, building it or just trying to understand what your consent needs, the zone is the starting input. Thermly takes it from here: construction R-values against measured envelope areas, compared with the H1/AS1 reference building under the Calculation Method.

Start a Calculation Method project

Primary standard

H1/AS1 Sixth Edition, Appendix C and Table 2.1.2.7, in force from 27 November 2025. Council table last checked . Open the MBIE PDF.

Check the postcode

If you need to confirm the postal address itself, use the NZ Post address and postcode finder.

This finder is explanatory support, not a substitute for the cited standard, amendments or project-specific professional judgement. Read the complete H1 compliance guide for the Calculation Method workflow and transition dates.